your question is not vague enough. and the answer is three...licks to get to the tootsie roll center of a tootsie pop.
i run a tad more than 2 gal for a sprint. add another half gal for a solo. i try not to run the light solid.
Fill it up to the top of the hump in the tank. run a practice session. measure how much you used and divide by the number of laps. then multiply by the number of laps in the race (don't forget about sighting lap and cool down). Run the tank down to as close to empty as you can and then add the appropriate amount of fuel as you need. Be careful, you don't want to be like the entire Honda team at Daytona last year. Oh yeah, every track is slightly different.
As much as it takes to cross the finish line and then a little more... This goes for both types of races... You left out a number of things - what track, what kind of fuel, etc.
dont know why everyone is giving you such a hard time....put 2-2.5 gallons in it and it'll be fine. if you really wanted to break it down, its gonna get 20-22mpg under race conditions.
You're riding through the desert on your boat. You get a flat tire. How many pancakes does it take to build a house? Blue because ice cream has no bones.
If you weigh 300 pounds like most of us LW guys do, just fill the thing...it's not like you're adding a statistically significant amount of weight.
Are you faster then me? If yes then you need .5 gallons per sprint, and 1 gallon per solo. Should be good for every track. Maybe a little less for VIR, and Nelson. Those tracks are real easy on gas.
Fixed it for ya. And I generally leave with a full tank for both. Sorry...but 7-10 lbs ain't gonna make me THAT much faster. I'd rather finish every race....and not lose due to running out of gas. JMNSHO. :P
I put a full tank in my pit buddies bike when he isn't looking and about half as much in mine. I figure since I outweigh him by 10 pounds it makes us even. Sorry, I'm sitting in the middle of the desert at 1:40 a.m. (our time) and I'm just happy to be able to get on the internet and BBS again and couldn't resist.